Arrangement for connecting two marine vessels

ABSTRACT

A first and a second block-and-tackle arrangement each have first end portions which can be mounted on a marine vessel to be pushed, and second end portions which are pivotably connected with one arm of a respective two-armed rocker. The rocker elements are mounted on a pushing vessel in the region of opposite lateral sides of the hull thereof and have freedom of turning movement about vertical axes, which turning movement is resiliently opposed by hydraulic cylinder and piston units acting upon the respective other arm.

o l I United States Patent. [1 1 1111 3,802,375 Janssen Apr. 9, 1974 [54] ARRANGEMENT FOR CONNECTING TWO l00,l97 2/1870 Shepardson ll4/236 MARINE SS 1,338,530 4/1920 Roe ll4/236 [75] Inventor: Hans Georg Janssen, Bremerhaven, FOREIGN T TS OR APPLICATIONS Germany 1 641,617 12/1963 Belgium 1l4/235 R [73] Assignee: Aktien-Gesellschaft Weser, Bremen,

Germany Primary Examiner-Duane A. Reger 1 Assistant Examiner-D. C. Butler Filed: 1 1972 Attorney, Agent, or Firm-Michael S. Striker [21] Appl. No.: 302,591

, [57] ABSTRACT [30] Foreign Application Priority Data A first and a second block-and-tackle arrangement Nov. 6, 1971 Germany 7141966 each have first end P Q which can be mounted on a marine vessel to be pushed, and second end portions 521 US. Cl. 114/235 R, 115/6 which are pivotably connected with one arm of a [51] Int. Cl. i B63b 21/56 spective two-armed focker- The rocker elements are [58] Field of Search 114/235, 236, 70, 2; mounted on a Pushing vessel in the region of Opposite 115 7 lateral sides of the hull thereof and have freedom of turning movement about vertical axes, which turning 5 R f r n Cited movement is resiliently opposed by hydraulic cylinder UNITED STATES PATENTS and piston units acting upon the respective other arm.

3645,2225 2/1972 Lunde 114/235 R 5 Claims, 1 Drawing Figure BACKGROUND OF THE INVENTION The present invention relates generally to an arrangement for connecting two marine. vessels, and more particularly for connecting a marine vessel which is to be maneuvered by pushing with another marine vessel which is capable of effecting such pushing.

Tug boats and other marine vessels of this type are frequently used not only for pulling of other vessels, but for pushing them. This is particularly true in harbors where it is necessary to maneuver the non-powered vessel into a particular position or location, an operation which cannot be done by pulling it in many instances, so that it isnecessary to resort to pushing. In such applications the bow of the tug, as the pushing vessel will hereafter be called for convenience, is connected with the stern of the lighter, as the pushed vessel will hereafter be called for convenience. The vessels are then so connected that they can be displaced relative to one another about a vertical axis, which is located at or in the region of the area of contact between the two vessels. This makes it possible for the tub not only to push the lighter but also, by changing its position so that its own longitudinal axis is inclined with reference to that of the lighter, to use the tug as a rudder.

The displacement of the tug with reference to the lighterfor'purposes of using thetug as a rudder, requires some means for effecting such displacement other than the control instrumentalities of the tug itself, because these alone would not be able to maintain the tug in the final desired positionrelative to the lighter. It is therefore known to provide lateral block-andtackle arrangements, which are connected at opposite ends of the lighter and to the tug, being located laterally of the tug hull. The ropes of these arrangements are each secured to drums of winches mounted on-board of the tug. In order to obtain a desired tension on the ropes, and to prevent excessive tension on them as would occur if the vessels perform'rolling movements, it is known in the art to mount cylinder and piston units on deck of the tug, with these units being directly connected'with one end of the block-and-tackle arrangements, that is with that end which is secured on the tug itself. The other end of these ropes of course is secured to the drum of the respective winch. The cylinder and piston units thus can compensate for length variations in the length of the block-and-tackle arrangements, but in order to obtain the possibility of significant compensation for significant variations, which is necessary because of the given circumstances, rather large cylinder and piston units must be provided. Another reason for providing such large units is that it is desired that the ropes of the block-and-tackle arrangements be always subjected to a substantially uniform magnitude of tension which should be maintained, independent of the devices and units, thus cutting down further on the available space. The necessity of mounting in this already severely limited space the large cylinder and piston units of the priorart construction is evidently undesirable, aside from the fact that it interferes with the proper operation of onboard personnel and is particularly a source of danger for the tug boat crew.

SUMMARY OF THE INVENTION deck space for its mounting on the tug, and yet can achieve all the desired advantages.

In keeping with these objects, and others which will become apparent hereafter, one feature of the invention resides, briefly stated, in an arrangement for connecting a marine vessel to be maneuvered by pushing with another marine vessel capable of effecting such pushing. This novel arrangement comprises first and second block-and-tackle means having first end portions adapted to be mounted on the vessel to be pushed, and second end portions. A pair of rocker elements are mounted on the pushing vessel in the region of opposite lateral sides of its hull for turning movement about an axis, with each of the rocker elements having two arms located at opposite sides of the respective axis and each second end portion being connected with one of these arms. Biasing means acts upon the respective other arm and yieldably resists turning movement of the respective rocker element about the associated axis.

The arms are mounted for turning about upright axes, usually vertical or substantially vertical, and the elongation of the arms itself is transversely to the longitudinal centerline of the vessel. The mounting is such that one arm of each rocker extends outwardly beyond the hull, and it is to this arm that one end of the blockand-tackle unit is secured. This means that the blockamount of rolling that might occur and tend to change 7 the tension.

The operation of these prior-art arrangements is essentially satisfactory. The area in which problems exist, however, has to do with the necessarily large size of the cylinder and piston units. Tugs are relatively small marine vessels on which space, especially deck space, is at a premium. Usually the deck also carriesa variety of and-tackle units are located outwardly spaced from the hull and that fouling or other interference cannot occur if the ropes of the block-and-tackle units go slack for any reason, because they can freely hang through and a contact of their warping blocks with the hull of the tug is avoided.

The other arm of the respective rocker unit is connected articulately with a cylinder and piston unit, preferably a hydraulic cylinder and piston unit which in turn is secured to the deck of the tug. However, because of the arrangement according to the present invention the cylinder and piston units can be much more compact than those known from the prior art so that the arrangement requires substantially less space than was heretofore possible. In particular, if the length of the two arms of the rocker of each rocker unit is made unequal, an appropriate selection of the respective length makes possible a desired degree of force magnification, so that the dimensions of the arrangement can be varied within relatively wide possibilities simply by varying the amount of force magnification and thereby varying the amount of biasing action which is required.

In it particularly advantageous that in the construction according to the present invention one warping block of an associated block-and-tackle unit is connected with the arm of the respective rocker unit which extends outwardly beyond the hull, so that length variations between the pivotal connections of the block-andtackle units to the rocker arm at the one hand and to the stern of the lighter at the other hand, will be reduced appropriately, so that rolling movements between the vessels of large magnitude will result in only small displacements of the rocker units.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, toegther with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING The single FIGURE is a diagrammatic illustration of one embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Discussing the drawing now in detail it will be seen that reference numeral 1 designates a diagrammatically shown tug, for instance a harbor tug which is well known. The tug l is intended for maneuvering a lighter 2 by pushing it, with the lighter 2 being also shown diagrammatically and only fragmentarily. The connection in motion-transmitting relationship can be effected in various ways. In the illustrated embodiment the bow of the tug l is provided with a vertically arranged motiontransmitting member 3 which extends into a recess of a traverse member 4 which is mounted horizontally at the stern of the lighter 2 and can shift vertically in this recess, so that relative vertical displacement of tug l and lighter 2 is possible with the motion of the waves.

At opposite lateral sides of the tug 1 are arranged respective block-and-tackle units 5 and 6 which connect the tug 1 and the lighter 2 with one another. In addition, they permit a displacement of the tug l with reference to the lighter 2 about a vertical axis passing approximately through the point of contact between the elements 3 and 4. The multiple block-and-tackle units 5 and 6 have shear blocks which are respectively connected to the stern of the lighter 2 and approximately mid-way of the hull of the tug 1. These shear blocks are designated with reference numerals 7 and 8 and are pivoted as far as possible outwardly away from the longitudinal center line of the lighter hull in order to obtain the displacement of the tug with reference to the lighter 2 (when desired) with minimum possible force.

The other shear blocks 9 and 10 are connected to the outwardly directed arms of respective rocker units or elements 1 l and 12, with these extending outwardly beyond the lateral edges of the tug hull. Each of theseunits 11 and 12 is mounted on deck of the tug 1 for turning movement about an at least substantially vertical axis 11a and 12a, respectively. The inwardly directed arms of the units 11 and 12 are each articulately connected with a cylinder and piston unit 13 and 14, respectively, which is advantageously hydraulically operated, preferrably via a pressure equalizing vessel.

The operation of the novel arrangement is clear, in that any tendency of the units 11 and 12 to turn about their respective axes under the influence of stresses exerted via the associated block-and-tackle units is resiliently counteracted by the respective cylinder and piston units, so that the block-and-tackle units, or the ropes thereof, are always maintained under at least substantially uniform tension. Yet, because of the particular arrangement described, the size of the overall construction (rocker elements and associated cylinder and piston units) can be much smaller than anything that is known from the prior art.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.

While the invention has been illustrated and described as embodied in an arrangement for connecting two marine vessels, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.

I claim:

1. An arrangement for connecting a marine vessel to be maneuvered by pushing with another marine vessel which is capable of effecting such pushing and has a longitudinal axis, comprising first and second blockand-tackle means having first end portions; a pair of rocker elements mounted on the pushing vessel remote from the vessel to be pushed in the region of opposite lateral sides of its hull for turning movement about an axis, each of said rocker elements having two arms located at opposite sides of the respective axis and of which a first one extends outwardly away from said axis and a second one extends inwardly towards said axis, each of said second end portions being connected with one of said first arms; and biasing means comprising fluid-operated cylinder-and-piston units extending longitudinally of said axis and each being connected with one of said second arms and yieldably resisting turning movement of the respective rocker element about the associated axis so as to normally maintain said rocker elements extending normal to said axis.

2. An arrangement as defined in claim 1, wherein said rocker elements are mounted for turning move ment about upright axes.

3. An arrangement as defined in claim 1, wherein said biasing means is articulately connected with the respective second arm.

4. An arrangement as defined in claim 1, wherein said biasing means comprises a pair of hydraulic cylinder and piston units.

5. An arrangement as defined in claim 1, wherein each of said block-and-tackle means comprises a warping block at the respective second end portion; and wherein each of said warping blocks is articulately connected with the respective first arm. 

1. An arrangement for connecting a marine vessel to be maneuvered by pushing with another marine vessel which is capable of effecting such pushing and has a longitudinal axis, comprising first and second block-and-tackle means having first end portions; a pair of rocker elements mounted on the pushing vessel remote from the vessel to be pushed in the region of opposite lateral sides of its hull for turning movement about an axis, each of said rocker elements having two arms located at opposite sides of the respective axis and of which a first one extends outwardly away from said axis and a second one extends inwardly towards said axis, each of said second end portions being connected with one of said first arms; and biasing means comprising fluid-operated cylinder-and-piston units extending longitudinally of said axis and each being connected with one of said second arms and yieldably resisting turning movement of the respective rocker element about the associated axis so as to normally maintain said rocker elements extending normal to said axis.
 2. An arrangement as defined in claim 1, wherein said rocker elements are mounted for turning movement about upright axes.
 3. An arrangement as defined in claim 1, wherein said biasing means is articulately connected with the respective second arm.
 4. An arrangement as defined in claim 1, wherein said biasing means comprises a pair of hydraulic cylinder and piston units.
 5. An arrangement as defined in claim 1, wherein each of said block-and-tackle means comprises a warping block at the respective second end portion; and wherein each of said warping blocks is articulately connected with the respective first arm. 